Pipe-bending tool



March 25, 1930.

P-IPE BENDING TOOL Filed March 12, 1929 INVENTOR WITNESSES Qififl- F? a I .6. M Q c ATTORNEY A. ALLEN Patented Mar. 25, 1930 ew-sun an, or crnomnnm, om'o PIPE-BENDING moon Application filedMareh 12, 1929, Serial No. 346,388.

'My'invention relates to pipebending tools and more particularly toimprovements in the tool'set forth in mycopending application Serial Number- 166,200, filed February 5, 1927 now issued asPatent'No'; 1,7l2,4:14,dated May7,1929.

An object of sized thin wallconduitsas' well as-the usual standard rigid heavy wall conduit.

- Further the invention provides a bending tool of-thischaracter which will not cause the conduit to flatten out when being bent,

but to the contrary will cause theconduit to assumea substantially circular configuration in cross section." I a Still another object of the invention isto provide a bending tool which will positively grip the'conduit so as to prevent slipping of I tor.

tool having coacting ofisetj'aws, one of which is provided :with'an "arrangement of teeth whereby the initial pressure exerted on the conduit will allow the sametoexpand or as-' sume an egg shape 1n cross section and a further pressure on 4 same into its original cross sectional'shape.

Withthe preceding and other objects and advantages in the mind the invention'consists in the novel combination of elements, c0n-' structions" andarrangements of parts andoperations to behereinatter morefully "de scribed,', claimed'- and illustrated in the ac- 'comp a'nying drawings, wherein 2 Figure 1 is side' elevation of my-improved 'tool having a length of conduit engaged 40 therewith;

Fig. 2 is an elevation taken at right angles to Fig. 1

Fig. 3 isa vertical sectional view of the def vice and showing the conduit bent, the conduit-being indicated by broken lines;

Fig.4 is a transverse section taken on-line 4r4 of Fig. 3; if: w

= Fig.:5 :isa 'si ilan-view illustrating the 1 cross sectional shape otthe conduit after the initial pressure the invention is to provide a pipe bending tool which may be conveniently and -efiectively employed to bend various the tool and incidental to' the opera- More specifically the invention provides a-' the conduitwill forcethe has been,applied;

' Fig.6 is a similar view and showing the conduit after thefull bending pressure has been applied,the dotted line indication'illustrating the true outline of the conduit after the bend hasbeenefiected'; V

, Fig. 7 is a view'takenon line 4- 4: similar to Figure 4 but showing a smaller pipein position for bending;

Fig. 8 is a similar view, thefull line posi-' tion of the'pipe indicating the shape of the same after the initial pressure andthe dotted lines indicating the shape of the conduit after the full bending pressure hasfbeen applied; and 7 Fig. 9 is'a side elevation of the device, partly in section and disclosing a length of conduit engaged therewith.

Referring tothe invention in detail an elongated metallic head or casting isidesignated at 5 and is formed with-a cylindrical exteriorlythreaded shank 6 uponits under face. The shank 6 extends obliquely with respect to the vertical and receives a removable tubular handleor lever7. .7 At its opposite end the headis formed with a downwardly curved extension or jaw 10 whose curve corresponds to the curve to be given to the conuitto be bent. T I

A longitudinal groove extends throughout the length of the upper face of the head and extension and has a substantially concave. or depressed bottom walllland'divergent side walls 12."; a

In practice the bend to the'conduit starts from the inner endof the curved extension or jaw and from-this pointto' the'outer end of f thismember, the groove is formed with paral- -lel teeth 13 which extend transversely along the side walls 12 and bottom'wall' 11.; At the lower ends of thefside walls the teeth are formed with inwardly directed lateral shoulders 14 which present longitudinally aligned rows of bearing points for the conduit when initial pressure has been applied throughthe medium of the lever 7 Below the shoulders 1 1 the teeth are'formed with less prominent T shoulders 15 which are steppedfrom the shoulders 14 and are located upon opposite sides. of thelongitudinal center of the bottom wall 11 of the groove. I

transversely extending teeth 19 are fashioned in the groove 18 at theends of the .jaw 17,

one set of which is brought into play in" making the bend as disclosedin-Fig. 8. other set of teeth are utilized in making short left hand bends. In this connection it will be apparent that the conduit will be arranged "in the device in the reverse manner from that disclOsedinFig'S. p

The under face o f't'he jaw 17 is further provided with an inverted V-shaped recess 20, one bevelled wall of which will be utilized as a protection housing for the threaded end of the pipe in making short bends 'or elbows.

bendone end of the conduit will be positioned against "the jaw 17 with the threaded end projecting into the recess Twhile the conduit proper will be engaged by thej aw 10. As disclosed in Fig. 9 the threaded end of the conduit is received in the recessQO and is protected against mutilation by reason of the conduitbein'g engaged by theteeth in advance of the recess. 7 I j v In the operation ofjthe device the conduit is firstengaged between the jaw 17 and 'ther jaw 10. As'the'casting is rocked to the right by means of the hand j .ver, pressure is exerted against the conduit "by against the pipeiby the-tooth at the inner end of thejaw 10 and the far end of the jaw 17. Due tothe arrangement of the teeth in fthe groove {in the jaw 10 the initial pressure expands orcauses the conduit to assume the egg-shape disclosed in "Fig. 5 bringing the under face of the conduit against the longitudinally aligned shoulders 14 and 15. By reason of th650011dl1it being'limited in its expansion by abutting the shoulders 15, con tinued strain on the conduit-causes thejshoulders 15' to pressagainst the underfaceof the conduit and bend the same back to normal cross sectional shape as; indicated in dotted lines in Fig. 5. In addition to the-teeth actingas above stated these teeth and the teeth 19 successivelyi'grip the conduit thus insuring positive'grip without any d'anger'of the tool slipping.

r The above outlined mode 'of 'operationapplies to the bending 'of'three-qu'arter inch j thin'wall conduit andinberiding one-half.

' 'inchjconduit the'same action takes'place except the'conduitfirst rests upon the'shoul- 6 ders 14 and out of contact with theporti'ons heavy-walled or rigid conduit.

That is to say in making a short right hand the jaws. The first pressure is exerted angles from the web and overlying the (cast tion to its inner face-"andbeingioffsetrfrom of the teeth on the divergent walls of the groove as disclosed in Fig. 7 When pressure is brought to bear on this size conduit it initially expands to the full line position disclosed in Fig. 8 so that upon continuous application of pressure the conduit being un able to expand any further than the bottom wall 11 of the groove theteeth 12 atthis point press against the conduit to force the same to its original configuration as disclosed in broken lines in this figure. Inasmuch as no expansion occurs in bending heavy walled rigid conduits they may be bent in the same manner as thin walled conduits. That is to say the bending action is obtained by the teeth 'on the divergent walls of the {grooveandfthe teeth on the jaw 17. I I

From the above description it will be manifest that I have provided atojol which or can be readily used forbending various sized thin walledconduits as well as thestandard? rIclaim; j v p 1. In a pipe bending tool, :a roasting having an attaching shank upon its under face and a longitudinally curved channelled .jaw=- atone end, a second ijawcarried by the'castingand offset inwardly from thecurvedjaw, the inner face of the curved jaw having transversely stepped surfaces whereby to perm it .95 the pipe to initially expand to an irregularconfiguration and then forced back into nor- .mal configuration during the bending operation. 7

'2. Ina bendingitool, a easting ihavinglan 7100' attaching shank g'projecting from its under. face, a downwardly curved channelledjaw formed with one end of the casting, a web formed with the 1 casting atone "side of the channelled jaw, a aw projecting at right ing and cooperating with the channelledfjaw -1n grasping a pipe therebetween, thefchannelled jaw having longitudinal; rows :Iof shoulders located upon oppositesides of 'the longitudinalcenter of theljaw, and 'with one row stepped beyondthe other, so that appli- I cationof pressureagainst the pipeiwill cause the latter to engage theshoulders'upon cross 7 forced into normal' cross section-shape.

3. In a bending tool, a casting-having-an attaching member upon one'face; and a downsectional distortion of the'flpipei andthereby x j aw having divergent side walls and a substantially concave bottom wall, teeth'extending' transversely of the bottom and side Walls, I the teeth having stepped 4 surfaces to .c-allow for expansion of the conduit and the .subse;-,,,. quent' reshaping when pressure is brought to bear upon the latter, and afs'econdjaw-fixed to" the casting and disposed iniopposedirelathe channelled jaw.

4. In a variable diameter pipe bending tool, a casting having an attaching shank projecting from its under face and a curved channe11ed jaw at one end upon one side of the attaching shank, the curved jaw being. substantially V-shaped in cross section and hav ing toothed stepped surfaces whereby to accommodate pipes of various diameters and to reshape the expanded pipe during the bending operation.

ANDREW B. ALLEN. 

